Qt MainWindow中的OpenSceneGraph集成

我有以下代码，它是OpenSceneGraph（https://github.com/openscenegraph/osg/blob/master/examples/osgviewerQt/osgviewerQt.cpp）给出的用于将OSG与Qt集成的代码的修改：

OSGViewer.h

#ifndef OSGVIEWER_H
#define OSGVIEWER_H

#include <QTimer>
#include <QApplication>
#include <QGridLayout>

#include <osgViewer/CompositeViewer>
#include <osgViewer/ViewerEventHandlers>

#include <osgGA/MultiTouchTrackballManipulator>

#include <osgDB/ReadFile>

#include <osgQt/GraphicsWindowQt>

#include <QGLWidget>

class ViewerWidget : public QWidget, public osgViewer::CompositeViewer
{
public:
    ViewerWidget(QWidget* parent = 0, osgViewer::ViewerBase::ThreadingModel threadingModel=osgViewer::CompositeViewer::SingleThreaded);   

    QWidget* addViewWidget( osgQt::GraphicsWindowQt* gw, osg::Node* scene );

    osgQt::GraphicsWindowQt* createGraphicsWindow( int x, int y, int w, int h, const std::string& name="", bool windowDecoration=false );

    virtual void paintEvent( QPaintEvent* event ) { frame(); }

    QTimer _timer;
};

#endif // OSGVIEWER_H

OSGViewer.cpp

#include "OSGViewer.h"

ViewerWidget::ViewerWidget(QWidget* parent, osgViewer::ViewerBase::ThreadingModel threadingModel) 
{
    setThreadingModel(threadingModel);

    connect( &_timer, SIGNAL(timeout()), this, SLOT(update()) );
    _timer.start( 10 );
}

QWidget* ViewerWidget::addViewWidget( osgQt::GraphicsWindowQt* gw, osg::Node* scene )
{
    osgViewer::View* view = new osgViewer::View;
    addView( view );    

    osg::Camera* camera = view->getCamera();
    camera->setGraphicsContext( gw );

    const osg::GraphicsContext::Traits* traits = gw->getTraits();

    camera->setClearColor( osg::Vec4(0, 0, 0, 1.0) );
    camera->setViewport( new osg::Viewport(0, 0, this->width(),   this->height()) );
    camera->setProjectionMatrixAsPerspective(30.0f, static_cast<double>(traits->width)/static_cast<double>(traits->height), 1.0f, 10000.0f );

    view->setSceneData( scene );
    view->addEventHandler( new osgViewer::StatsHandler );
    view->setCameraManipulator( new osgGA::MultiTouchTrackballManipulator );
    gw->setTouchEventsEnabled( true );
    return gw->getGLWidget();
}

osgQt::GraphicsWindowQt* ViewerWidget::createGraphicsWindow( int x, int y, int w, int h, const std::string& name, bool windowDecoration )
{
    osg::DisplaySettings* ds = osg::DisplaySettings::instance().get();
    osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
    traits->windowName = name;
    traits->windowDecoration = windowDecoration;
    traits->x = x;
    traits->y = y;
    traits->width = w;
    traits->height = h;
    traits->doubleBuffer = true;
    traits->alpha = ds->getMinimumNumAlphaBits();
    traits->stencil = ds->getMinimumNumStencilBits();
    traits->sampleBuffers = ds->getMultiSamples();
    traits->samples = ds->getNumMultiSamples();

    return new osgQt::GraphicsWindowQt(traits.get());
}

MainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "OSGViewer.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:
    //void onCreateView();

private:
    Ui::MainWindow *ui; 
    osg::ref_ptr<ViewerWidget> m_osgViewer_right, m_osgViewer_left;
};

#endif // MAINWINDOW_H

MainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    m_osgViewer_left = new ViewerWidget(this);
    ui->left = m_osgViewer_left->addViewWidget(m_osgViewer_left->createGraphicsWindow(0,0,100,100), osgDB::readNodeFile("cessnafire.osg") );        
    m_osgViewer_left->show();

    m_osgViewer_right = new ViewerWidget;
    ui->right = m_osgViewer_right->addViewWidget(m_osgViewer_right->createGraphicsWindow(0,0,100,100), osgDB::readNodeFile("cow.osgt") );       
    m_osgViewer_right->show();

    ui->gridLayout->addWidget( ui->left, 0, 0 );
    ui->gridLayout->addWidget( ui->right, 0, 2 );   
}
/* ------------------------------------------------------- */
MainWindow::~MainWindow()
{
    delete ui;
}

虽然我可以在MainWindow中使用两个不同的QWidget渲染两个对象，但我总是在MainWindow后面弹出另外两个独立的空窗口 . 如果我关闭它们，那么我无法在MainWindow中渲染我的模型 . 任何想法如何解决这个问题？我是OpenSceneGraph的新手 .